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Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa
Thesis (MSc)--Stellenbosch University, 2025.
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613859758473216 |
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| access_status_str | Open Access |
| author | Raath, Ruan Francois |
| author2 | Kisters, Alexander |
| author_browse | Kisters, Alexander Raath, Ruan Francois |
| author_facet | Kisters, Alexander Raath, Ruan Francois |
| author_sort | Raath, Ruan Francois |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2025.
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| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132488 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:42:50.594Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132488 Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa Raath, Ruan Francois Kisters, Alexander Penn-Clarke, Cameron Stellenbosch University. Faculty of Science. Dept. of Earth Sciences. Geology, Stratigraphic -- South Africa -- Western Cape -- Klipheuwel Group Sedimentation and deposition -- South Africa -- Western Cape -- Klipheuwel Group Geology, Structural -- South Africa -- Western Cape Tectonics (Geology) UCTD Thesis (MSc)--Stellenbosch University, 2025. Raath, R. F. 2025. Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/48d1c605-0abf-439e-b597-2d359a7b9c6d ENGLISH ABSTRACT: The coarse-siliciclastic Klipheuwel Group in the Western Cape is a rift-type succession that provide critical insight into the tectonic transition from Gondwana amalgamation to divergent tectonics in SW Gondwana, preceding the deposition of the Cape Supergroup. This study is aimed at providing a comprehensive stratigraphic characterisation and tectonic interpretation of the Klipheuwel Group based on the integrated research into the lithological, structural, provenance and geochronological architecture and inventory of the rocks. Deposition of the alluvial Klipheuwel Group, previously assumed to be Cambrian in age, is constrained to the late Cambrian based on a maximum depositional age (MDA) of 488.7 ± 4.8 Ma. The rocks are preserved in isolated, NW-trending depositories as erosional relics that describe distinctly different northern and southern depocentres in the Western Cape. Rocks of the northern depocenter are preserved at three localities, Eendekuil, Redelinghuys and Elands Bay. Here, the Klipheuwel Group is characterised by laterally persistent braided fluvial facies forming multi-storey "braided sheet" deposits. The rocks exhibit gentle dips and thicknesses of 300-450 m, reflecting sedimentation on a peneplaned Pan-African basement. Provenance studies reveal a bimodal detrital zircon-age distribution (1200-1030 Ma and 640-540 Ma), with autochthonous and allochthonous detritus sourced from recycled, likely South American Brasilliano orogenic belts and the Namaqua Metamorphic Complex to the northeast, with mainly east-trending palaeocurrents. The southern depocentre comprises two localities, the Klipheuwel Group type locality, at Klipheuwel quarry, and Klapmutskop. Here, the sequence of coarse-clastic rocks is > 2000 m comprising laterally discontinuous channelised, braided fluvial facies. Deposition was controlled by actively subsiding half-graben structures that formed along reactivated fault strands of the Colenso Fault in the Pan-African basement. Provenance data indicate an autochthonous source preserving less competent clasts through rapid burial. The distinctly unimodal detrital zircon-age distribution (560-520 Ma) agrees with the derivation of detritus from the nearby Cape Granite Suite and a northwestern palaeocurrent paralleling the Colenso Fault. On a regional scale, the rift-type deposition of the Klipheuwel Group coincides with a tectonothermal event that affected large parts of SW Africa. This includes the emplacement of post Pan-African, A-type granites at ca. 510-505 Ma (Kuboos-Bremen line in Namibia and Klipberg Granite in the Western Cape), the emplacement of mafic dykes in southern Namaqualand (ca. 487 Ma) Ma) and Ar-Ar whole-rock and mica ages (495-485 Ma) of metapelitic units in the Saldania Belt, Vanrhynsdorp Basin and the southern Gariep Belt. The bimodal magmatism and heating of the crust indicates crustal thinning and mafic underplating. The correlation of the Klipheuwel Group with similarly-aged sedimentary and volcano-sedimentary, rift-type successions in South Africa, South America and Antarctica indicates regional-scale extension and crustal thinning of the peri-Gondwanan margin. Extensional stresses associated with rifting of individual basins point to stretching and thinning of the crust and associated magmatic underplating due to slab-roll back along the convergent margin, the Terra Australis, that formed outboard of SW Gondwana. As such, the small, rift-type basins of the Klipheuwel Group form part of pre-Cape Supergroup, post-Pan-African extensional tectonic processes that seem to have affected a much larger region, following within only 10-20 m.y. of the amalgamation of SW Gondwana. Subsequent basin formation that allowed for the deposition of the extensive Cape Supergroup is interpreted to have been driven by thermal subsidence related to the earlier episodes of mafic magmatic underplating. AFRIKAANSE OPSOMMING: Die growwe-silikiklastiese Klipheuwel Groep in die Wes-Kaap is 'n slenk-tipe opeenvolging wat belangrike insigte bied in die tektoniese oorgang van Gondwana-samesmelting na uiteenlopende tektoniek in SW Gondwana, wat die afsetting van die Kaapse Supergroep voorafgegaan het. Hierdie studie is daarop gemik om 'n omvattende stratigrafiese karakterisering en tektoniese interpretasie van die Klipheuwel Groep te verskaf, gebaseer op geïntegreerde navorsing oor die litologiese, strukturele, brongebied- en geochronologiese argitektuur en inventaris van die gesteentes. Afsetting van die spoel Klipheuwel Groep, voorheen vermoed om Kambries van ouderdom te wees, word beperk tot die laat-Kambriese periode gebaseer op 'n maksimum afsettingsouderdom van 488.7 ± 4.8 Ma. Die gesteentes word bewaar in geïsoleerde, NW- gerigte afsettingsplekke as erosionele oorblyfsels wat duidelik verskillende, noordelike en suidelike afsettingsplekke, in die Wes-Kaap beskryf. Gesteentes van die noordelike afsettingsplekke word bewaar by drie lokaliteite: Eendekuil, Redelinghuys en Elandsbaai. Hier word die Klipheuwel Groep gekenmerk deur lateraal aaneenlopende, gevlegte fluviale fasies wat multi-verdieping “gevlegte plaat”-afsettings vorm. Die gesteentes vertoon sagte hellings en diktes van 300-450 m, wat sedimentasie op 'n skiervlakte van die Pan-Afrikaanse vloer weerspieël. Brongebiedstudies toon 'n bimodale detritale sirkon-ouderdomsverspreiding (1200-1030 Ma en 640-540 Ma), met autochtoniese en allochtoniese detritus afkomstig van herwonne, waarskynlik Suid-Amerikaanse Brasilliano-orogeniese gordel en die Namaqua Metamorfe Kompleks in die noordooste, met hoofsaaklik ooswaartse paleostrome. Die suidelike afsettingsplekke bestaan uit twee lokaliteite, die kenlokaliteit van die Klipheuwel Groep, by Klipheuwel groef, en Klapmutskop. Hier bestaan die reeks growwe-klastiese gesteentes uit > 2000 m lateraal diskontinue, gekanaliseerde, gevlegte fluviale fasies. Afsetting is beheer deur aktiewe insakkende half-graben strukture wat gevorm het langs gereaktiveerde breuklyne van die Colenso Breuk in die Pan-Afrikaanse vloer. Brongebieddata dui op 'n autochtoniese bron wat minder bestande klaste bewaar deur vinnige begrawing. Die duidelik unimodale detritale sirkon-ouderdomsverspreiding (560-520 Ma) stem ooreen met die herkoms van detritus uit die nabygeleë Kaapse Graniet Suite en 'n noordwestelike paleostroom wat parallel loop met die Colenso Breuk. Op 'n streekskaal val die slenk-tipe afsetting van die Klipheuwel Groep saam met 'n tektonotermiese gebeurtenis wat groot dele van SW-Afrika beïnvloed het. Dit sluit in die inplasing van post-Pan-Afrikaanse, A-tipe graniete omstreeks 510-505 Ma (Kuboos-Bremen- lyn in Namibië en Klipberg-graniet in die Wes-Kaap), die inplasing van mafiese gange in suidelike Namaqualand (ca. 487 Ma) en Ar-Ar volgesteente- en mika-ouderdomme (495-485 Ma) van metapelitiese eenhede in die Saldania Gordel, Vanrhynsdorp Kom en die suidelike Gariep Gordel. Die bimodale magmatisme en verhitting van die aardkors dui op korsverdunning en mafiese onderplasing. Die korrelasie van die Klipheuwel Groep met soortgelyk-oue sedimentêre en vulkanies- sedimentêre, slenk-tipe opeenvolgings in Suid-Afrika, Suid-Amerika en Antarktika dui op streekskaalse verlenging en korsverdunning van die peri-Gondwaniese rand. Ekstensiespannings wat met slenking van individuele komme geassosieer word, dui op rekking en verdunning van die aardkors, asook verwante magmatiese onderplasing as gevolg van blad-terugrol langs die konvergente rand, die Terra Australis, wat buite SW Gondwana gevorm het. Sodanig, vorm die klein, slenk-tipe komme van die Klipheuwel Groep deel van pre-Kaapse Supergroep, post-Pan-Afrikaanse verlengingstektoniese prosesse wat waarskynlik 'n veel groter streek beïnvloed het, en wat binne slegs 10-20 miljoen jaar ná die samesmelting van SW Gondwana plaasgevind het. Die opvolgende kom vorming wat die afsetting van die uitgebreide Kaapse Supergroep moontlik gemaak het, word geïnterpreteer dat dit aangedryf was deur termiese insakking wat verband hou met vroeër episodes van mafiese magmatiese onderplasing. Masters 2025-06-09T14:14:46Z 2025-06-09T14:14:46Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132488 en Stellenbosch University vii, 154 pages : illustrations (some color), maps application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Geology, Stratigraphic -- South Africa -- Western Cape -- Klipheuwel Group Sedimentation and deposition -- South Africa -- Western Cape -- Klipheuwel Group Geology, Structural -- South Africa -- Western Cape Tectonics (Geology) UCTD Raath, Ruan Francois Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa |
| title | Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa |
| title_full | Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa |
| title_fullStr | Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa |
| title_full_unstemmed | Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa |
| title_short | Depositional setting, provenance and age of the Klipheuwel Group, Western Cape, South Africa |
| title_sort | depositional setting provenance and age of the klipheuwel group western cape south africa |
| topic | Geology, Stratigraphic -- South Africa -- Western Cape -- Klipheuwel Group Sedimentation and deposition -- South Africa -- Western Cape -- Klipheuwel Group Geology, Structural -- South Africa -- Western Cape Tectonics (Geology) UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132488 |
| work_keys_str_mv | AT raathruanfrancois depositionalsettingprovenanceandageoftheklipheuwelgroupwesterncapesouthafrica |